Balance weight for washing machine

ABSTRACT

Balance weight is mounted on a tub of a washing machine, balances the tub, and reduces the vibration of the tub. The balance weight comprises a plurality of weight plates piled up, and at least one coupling member securing the weight plates to the tub. The coupling member comprises at least one first member binding the weight plates into a body, and at least one second member stably securing the bound weight plates to the tub.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Application No. P2004-50315, filed on Jun. 30, 2004, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a washing machine, and more particularly, to a balance weight which is mounted on a tub of the washing machine for balancing the tub and reducing vibration of the tub.

2. Discussion of the Related Art

Washing machine is a representative home appliance for washing laundry using detergent and water. The washing machine is generally classified into two types, i.e., a top loading type and a front loading type based on the location of an opening for receiving the laundry.

The top loading type washing machine generally comprises a vertical tub for accommodating the laundry, a pulsater rotating in the tub and washing the laundry, and a lid provided on an upper surface of the washing machine for opening and closing the tub.

The front loading type washing machine generally comprises a horizontal tub for accommodating washing water, a horizontal drum provided in the tub for accommodating the laundry, lifters provided on an inner surface of the drum for lifting and dropping the laundry when the drum is rotated for washing, rinsing or dehydrating the laundry, and a door provided on a front surface of the washing machine for opening and closing the drum.

In the front loading type washing machine, a motor for driving the drum is mounted on a rear surface of the tub. Due to the motor, a rear portion of the tub is heavier than a front portion of the tube, thus, a balance weight is generally mounted on the front portion of the tub for balancing the tub. The balance weight provided on the front portion of the tub also makes the tub heavy. Thus, the balance weight not only balances the tube, but also reduces the vibration of the tub generated when the washing machine is operated.

The balance weight is generally made of heavy metal, cement, or concrete by casting. Since enough time is necessary for material of the balance weight to be solidified, it takes long time for manufacturer to produce the balance weight by casting. In addition, it is hard to change the weight of the contemporary balance weight. Thus, it is hard to adjust the weight of the balance weight in order to reflect errors occurred when the washing machine is assembled.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a balance weight that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to improve the structure of the balance weight for quick and easy assembly.

Another object of the present invention is to improve the structure of the balance weight for easy adjustment of the weight of the balance weight according to errors occurred during assembling process.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a balance weight for washing machine comprises a plurality of weight plates piled up, and at least one coupling member securing the weight plates to a tub of the washing machine.

Each of the weight plates may be configured to be bent in order to have a shape corresponding to a circumferential surface of the tub.

Each of the weight plates may comprise at least one hole in which the coupling member passes through. The hole may be configured to have an elliptical shape. Or, the hole may be configured to be elongated along with a direction substantially perpendicular to a bent line of the weight plate.

Each of the weight plates may comprise at least one first hole receiving the coupling member binding the weight plates into a body, and at least one second hole receiving the coupling member fitting the weight plates to the tub.

The coupling member may comprise at least one first member binding the weight plates into a body, and at least one second member fitting the weight plates bound by the first member to the tub. The first member may comprise a bolt and a nut or comprise a rivet.

The tub may comprise at least one boss provided on an outer surface of the tub and receiving the coupling member. The tub may further comprise at least one supplementary rib connected with the boss and the outer surface of the tub for reinforcing the strength of the boss. The weight plates may comprise at least one boss hole receiving the boss therein. The boss hole may be configured to be formed on partial weight plates located lower position.

In another aspect of the present invention, a balance weight for washing machine comprises a plurality of weight plates separably plied up, at least one first member binding the weight plates into a body and separable from the weight plates, at least one second member fitting the bound weight plates onto the tub and separable from the tub, and at least one boss provided on the tub and allowing the boss to be fitted thereto.

In another aspect of the present invention, a balance weight for washing machine comprises a case, a tub provided in the case and holding washing water therein, a rotatable drum provided in the tub and accommodating laundry therein, a motor driving the drum, a plurality of weight plates separably plied up, at least one first member binding the weight plates into a body, and at least one second member securing the weight plates bound by the first member to the tub.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment of the invention and together with the description serve to explain the principle of the invention. In the drawings;

FIG. 1 illustrates a cross sectional view of the washing machine according to the present invention;

FIG. 2 illustrates an exploded perspective view of weight plates of the balance weight according to the present invention;

FIG. 3 illustrates a perspective view of the weight plates and coupling members for fitting the weight plates to the tub;

FIG. 4 illustrates a cross sectional view of the weight plates and the coupling members in FIG. 3; and

FIG. 5 illustrates a perspective view of the balance weight mounted on the tub.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

As shown in FIG. 1, a horizontal tub 10 for holding washing water therein is provided in a case 1 of the washing machine. The tub 10 is suspended in the case 1 by a plurality of spring 34 and damper 32 respectively provided between the case 1 and the tub 10. The spring 34 and the damper 32 not only suspend the tub 10 in the case 1, but also reduce the vibration of the tub 10 generated during the operation of the washing machine.

An opening 11 is provided on a front portion of the tub 10, and an opening 2 is provided on a front surface of the case 1. The openings 2 and 11 are communicated with each other and facing each other. A door 3 is coupled to the front surface of the case 1 by a hinge, and opens and closes the openings 2 and 11. And, a gasket 15 is provided between the opening 11 of the tub 10 and the door 3 for preventing a leakage of the washing water stored in the tub 10.

A water supply hole (not shown in FIG. 1) is provided on an upper portion of the tub 10. The water supply hole communicates with a water supply hose 8 through a detergent box 7. Thus, the washing water is supplied into the tub 10 with detergent stored in the detergent box 7. A drain 16 for draining the washing water in the tub 10 is provided on a lower portion of the tub 10. The drain 16 communicates with drain hose 18 through a drain pump 17. Thus, contaminated washing water in the tub 10 is drained out through the drain 16 and drain hose 18 when the drain pump 17 is operated.

A rotatable horizontal drum 12 for accommodating laundry therein is provided in the tub 10. A plurality of apertures are provided on a circumference of the drum 12, thus, the washing water in the tub 10 can be introduced into the drum 12 through the apertures. A plurality of lifters 13 are projected from an inner surface of the drum 12. The lifters 13 lifts and drops the laundry in the drum 12 during a washing process, a rinsing process, and a dry process in order to improve performance of the processes.

The drum 12 is directly driven by a motor 20. As shown in FIG. 1. The motor 20 is mounted on an outer surface of the tub 10, and a shaft 22 of the motor 20 is connected to a rear of the drum 12 through the tub 10. A balance weight 100 is provided on an upper front portion of the tub 10 as shown in FIG. 1.

The balance weight 100 weighs approximately at similar to the motor 20 do in order to balance the tub 10. In addition, the balance weight 100 suppresses the generation of the vibration of the tub 10 during the operation of the washing machine and reduces generated vibration of the tub 10. FIG. 2 through FIG. 4 illustrates the structure of the balance weight 100 according to the present invention in detail. Thus, detailed structure of the balance weight 100 according to the present invention will be described in the following with reference to the drawings.

As shown in FIG. 2, the balance weight 100 comprises a plurality of weight plates 110 piled up, and at least one coupling member securing the weight plates 110 to the tub 10. Since the tub 10 has a cylindrical shape, it is preferable that the weight plates 110 are bent in order to have a shape corresponding to a circumferential surface of the tub 10. The weight plates 110, for example, have two bent lines in order that the weight plates 110 have two plane surface having different height level and slope between the two plane surface as shown in FIG. 2.

In this case, a first plane surface positioned in high level is fitted to an upper center portion of the tub 10, and a second plane surface positioned in low level is fitted to a side portion of the tub 10, as shown in FIG. 5. However, the present invention is not limited in that case. For another example, the weight plates 110 can be bent in order that the weight plates 110 have a curved portion corresponding to the outer surface of the tub 10. Further, it would be possible that the weight plates 110 are bent as the other shape according to the location to be installed and the structure of the installation.

The weight plates 110 are separably piled up, and coupled one another by a first member 140 before the weight plates 110 are secured to the tub 10. The first member 140 binds the weight plates 110 into one body for securing the weight plates 110 from disassembly of the weight plates 110, and thereby the weight plates 110 are not separated from one another.

The weight plates 110 includes at least one first hole 120. The first hole 120 is provided on each edge portion of the weight plates 110. All of the first hole 120 communicates with one another when the weight plates 110 are piled up. And, the first member 140 passes through the first hole 120 and bind all of the weight plates 110. The first member 140 comprises a bolt and a nut, or comprises a rivet. In case the first member 140 comprises the bolt and the nut, the first member 140 is liable to be separated from the weight plates 110, if necessary.

Although each of the first hole 120 is provided on the same location of each weight plate 110, all of the first hole 120 fail to communicate with one another after all of the weight plates 110 are piled up, if the weight plates 110 are bent or piled up inaccurately. In this case, it is hard for the first member 140 to be inserted into and to pass through the first hole 120. Thus, the first hole 120 has an elliptical shape as shown in FIGS. 2 and 3 in order that the first member 140 is inserted into the first hole 120 with ease.

In this case, the first hole 120 is configured to be elongated along with a direction substantially perpendicular to the bent line of the weight plates 110. Or, the elliptical first hole 120 is configured to be elongated along with a circumferential direction of the tub 10. If the first hole 120 has the elliptical shape as mentioned above, the first member 140 is liable to be inserted into and to pass through the first hole 120 with ease even if all of the first hole 120 are not aligned accurately.

There is no harm if the weight plates 110 are made of new and fresh plates. However, it is preferable that the weight plates 110 are made of used plate, especially waste plate cut away from large plate when the washing machine is fabricated. And then, the cost for producing the weight plates 110 is considerably saved. Meanwhile, the weight plates 110 can be bound without the first member 140. For example, the weight plates 110 can be bound by welding, and in this case the first hole 120 and the first member 140 are not indispensable to the balance weight 100 according to the present invention.

The weight plates 110 bound by the first member 140 are secured to the tub 10 by a second member 150. At least one boss 200 for allowing the second member 150 to be fitted thereto are projected from the outer surface of the tub 10, and at least one second hole 130 for receiving the second member 150 is provided on the weight plates 110. The second member 150 passes through the second hole 130 and then coupled to the boss 200 so that the second member 150 stably fits the weight plates 110 onto the tub 10. However, if necessary, the second member 150 can be separated from the boss 200 with ease.

When the washing machine is operated, the tub is vibrated. And, the weight plates 110 are heavy. Thereby a strong force can be applied to the boss 200 when the tub 10 vibrates. Thus, at least one supplementary rib 210 is provided between the outer surface of the tub 10 and an outer surface of the boss 200. The supplementary rib 210 stably support the boss 200 and reinforces the strength of the boss 200, thereby the damage of the boss 200 can be prevented.

At least one boss hole 135 is provided on the weight plates 110. The boss hole 200 allows the boss 200 to be inserted therein. It is possible that the boss hole 135 is provided on all of the weight plates 110. However, in the present invention, the boss hole 135 is provided on partial weight pates bound lower position among all of the weight plates 110 piled up as shown in FIGS. 3 and 4. The boss hole 135 has a diameter greater than the second hole's 130 and substantially as the same as the boss's 200.

For fitting the weight plates 110 to the tub 10, the boss 200 of the tub 10 is fitted into the boss hole 135 first. And then, the second member 150 passes through the second hole 130 and is connected to the boss 200. Thereby, the weight plates 110 are stably secured to the tub 10. If the boss hole 135 is provided as mentioned above, assembler can temporarily fit the weight plates 110 to the boss 200, and then can firmly fix the weight plates 110 to the tub 10 using the second member 150. Thus, the assembler can secure the weight plates 110 to the tub 10 very quickly and very easy.

As mentioned above, the balance weight according to the present invention is produced by simple processes including the cutting and the bending metal plates. Thus, time for producing the balance weight is reduced.

If heavy weight is necessary for balancing the tub, the assembler can pile a large amount of weight plates up and fit them to the tub with ease for balancing the tub. On the contrary, if light weight is necessary for balancing the tub, assembler can pile a small amount of weight plates up and fit them to the tub with ease for balancing the tub. More particularly, the assembler can adjust the weight of the balancing weight per a weight of one weight plate. As mentioned above, the assembler can adjust the necessary weight for balancing the tub with ease and very accurately.

Further, it is possible that waste plates generated when the washing machine is manufactured can be used as the weight plates. Thus, the cost for fabricating the washing machine is reduced. And, the environmental pollution caused by the waste plates can be prevented.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

1. A balance weight for washing machine comprising: a plurality of weight plates piled up; and at least one coupling member securing the weight plates to a tub of the washing machine.
 2. The balance weight as claimed in claim 1, wherein each of the weight plates is configured to be bent in order to have a shape corresponding to a circumferential surface of the tub.
 3. The balance weight as claimed in claim 1, wherein each of the weight plates comprises at least one hole in which the coupling member passes through.
 4. The balance weight as claimed in claim 3, wherein the hole is configured to have an elliptical shape.
 5. The balance weight as claimed in claim 3, wherein the hole is configured to be elongated along with a direction substantially perpendicular to a bent line of the weight plate.
 6. The balance weight as claimed in claim 1, wherein each of the weight plates comprises at least one first hole receiving the coupling member securing the weight plates from disassembly of the weight plates.
 7. The balance weight as claimed in claim 1, wherein each of the weight plates comprises at least one second hole receiving the coupling member securing the weight plates to the tub.
 8. The balance weight as claimed in claim 1, wherein each of the weight plates comprises at least one first hole receiving the coupling member binding the weight plates into a body; and at least one second hole receiving the coupling member fitting the weight plates to the tub.
 9. The balance weight as claimed in claim 1, wherein the coupling member comprises at least one first member securing the weight plates from disassembly of the weight plates.
 10. The balance weight as claimed in claim 9, wherein the first member comprises a bolt and a nut.
 11. The balance weight as claimed in claim 9, wherein the first member comprises a rivet.
 12. The balance weight as claimed in claim 1, wherein the coupling member comprises at least one second member passing through the weight plates coupled one another and securing the weight plates to the tub.
 13. The balance weight as claimed in claim 1, wherein the coupling member comprises at least one first member binding the weight plates into a body; and at least one second member fitting the weight plates bound by the first member to the tub.
 14. The balance weight as claimed in claim 1, wherein the tub comprises at least one boss provided on an outer surface of the tub and receiving the coupling member.
 15. The balance weight as claimed in claim 14, wherein the tub further comprises at least one supplementary rib connected with the boss and the outer surface of the tub for reinforcing the strength of the boss.
 16. The balance weight as claimed in claim 14, wherein the weight plates comprises at least one boss hole receiving the boss therein.
 17. The balance weight as claimed in claim 16, wherein the boss hole is configured to be formed on partial weight plates located lower position.
 18. The balance weight as claimed in claim 1, further comprising at least one hole provided on the weight plates; at least one boss provided on an outer surface of the tub and allowing the coupling member to be fitted thereto; and at least one boss hole provided on partial weight plates bound lower position and allowing the weight plates to be fitted onto the tub with ease.
 19. A balance weight for washing machine comprising: a plurality of weight plates separably plied up; at least one first member binding the weight plates into a body and separable from the weight plates; at least one second member fitting the bound weight plates onto the tub and separable from the tub; and at least one boss provided on the tub and allowing the boss to be fitted thereto.
 20. A balance weight for washing machine comprising: a case; a tub provided in the case and holding washing water therein; a rotatable drum provided in the tub and accommodating laundry therein; a motor driving the drum; a plurality of weight plates separably plied up; at least one first member binding the weight plates into a body; and at least one second member securing the weight plates bound by the first member to the tub. 